An alliance of political parties that played a key role in protests against Mohamed Morsi has called for demonstrations against a controversial new protest law.
30 June Coordinating Committee called on protesters to rally at Cairo's Talat Harb Square on Thursday afternoon, Aswat Masrya website reported.
The law will hinder social and political change, it said in a statement.
The committee includes the Egyptian Social Democratic Party, the Free Egyptian Party and the Democratic Front Party.
A protest in solidarity with protesters detained on Tuesday took place at Cairo's Abdeen Court on Thursday morning.
A separate protest in solidarity with journalists detained on Tuesday took place at the journalists' syndicate.
On Tuesday, dozens of people were arrested at a protest against an article in the draft constitution which allows military trials of civilians. They were also defying a new law which states police must give prior permission for protests.
On Wednesday, hundreds of people gathered in Talaat Harb and marched to the Shura Council against military trials of civilians and the protest law.